Eur. Phys. J. Plus (2014) 129: 180
https://doi.org/10.1140/epjp/i2014-14180-5

Regular Article

X-ray diffraction, magnetic and magnetocaloric properties of La_0.6Ca_0.4Mn_1−xFe_xO₃ (0 ≤ x ≤ 0.3) manganites prepared by the sol-gel method

¹ Faculty of Sciences of Sfax, Sfax University, B. P. 1171, 3000, Sfax, Tunisia
² Institut Néel, CNRS et Université Joseph Fourier, BP 166, F-38042, Grenoble cedex 9, France
³ National School of Engineers, Sfax University, LASEM B.P. W, 3038, Sfax, Tunisia

^* e-mail: ennasri.a@gmail.com

Received: 30 March 2014
Revised: 2 June 2014
Accepted: 5 July 2014
Published online: 26 August 2014

Abstract

Structural, magnetic and magnetocaloric properties of La_0.6Ca_0.4Mn_1−x Fe _x O₃ (0 ≤ x ≤ 0.3) manganites, synthesized using the sol-gel method, were investigated. Rietveld refinement of the X-ray diffraction patterns show that all our samples have single phase and crystallize in the orthorhombic structure with the Pnma space group. The unit cell volume increases when increasing the Fe content. Fe doping leads to a weakening of the ferromagnetic (FM) ordering at low temperature, the Curie temperature T _C decreases from 260 K for x = 0 to 44 K for x = 0.2. The magnetocaloric effect (MCE) was estimated, in terms of isothermal magnetic entropy change (−ΔS _M ), using the M(T, μ ₀ H) data and employing the thermodynamic Maxwell equation. The maximum value of the magnetic entropy change, (−ΔS _M ^max ) decreases from 3.66 J/kg K for x = 0 to 2.38 J/kg K for x = 0.1 under an applied magnetic field change of 5T. The magnetic-entropy change is 1.67 J/kg K at T _C (260 K) for a magnetic field of 2T and the RCP is 65 J/kg, which suggests the La_0.6Ca_0.4MnO₃ compound as a possible candidate for magnetic refrigerants near room temperature.